Chip-to-chip free-space optical interconnection using liquid-crystal-over- silicon spatial light modulator

Abstract

Free-space optical chip-to-chip interconnect offers a promising solution to bandwidth requirement. To move a light beam from a chip to another chip we need beam steerers which will steer the beam to desired direction. Different beam steering technologies have already been demonstrated to control the direction of light beam. These include different types of prisms, micro-electro-mechanical systems (MEMS), and Opto-VLSI processors. But all of those technologies have the limitations of having high optical losses & low signal-to-noise ratio. But the spatial light modulator (SLM) has several advantages over these. The large number of independently controllable elements in SLMs is expected to offer low optical loss as they are dynamic, controllable, and repeatable without moving parts. In this paper, we have proposed the concept of chip-to-chip optical interconnect that employs vertical cavity surface emitting lasers (VCSEL) and photo detectors (PD) in conjunction with two SLMs and Hologram design. This model for chip-to-chip free space optical interconnects uses SLM as beam steerer which is easy to control. Using our proposed model, we can have low optical losses, low crosstalk. This proposed chip-to-chip optical interconnection model can be applied in processor-memory and processor-processor communication. © Springer Science+Business Media B.V. 2010.